Protective tool for therapeutic material delivery device, cartridge for therapeutic material delivery device, and a therapeutic material delivery device

ABSTRACT

A protective tool for a therapeutic material delivery device prevents wrong sticking of the outer needle of the device after use and prevents dissipation of blood adhering to the outer needle and comprises a cover ( 8 ′A) and a cap ( 61 ) or stopper ( 65 ) attached to a forward end of said cover for protecting the forward end of the outer tubular needle ( 2 A), wherein said cover ( 8 ′A) is formed of a plurality of tubes ( 8 ′A 1, 8 ′A 2, 8 ′A 3 , . . . ) having different diameters that are formed so as to consecutively decrease from a forward place to the outer needle hub ( 2 B) in a backward place, and said tubes are thereby connected such that the cover ( 8 ′A) is extendable in the longitudinal direction, and a cartridge for use with the therapeutic material delivery device permits direct calibration of a radioactive source charged therein and comprises a transparent cartridge body ( 8, 18, 38 ) that holds said therapeutic material ( 10 ) inside and permits external visual observation of the therapeutic material ( 10 ) and a shielding outer tube ( 9, 19, 39 ) that is fitted on an outer circumference of the cartridge body, is slidable in the longitudinal direction of said cartridge body and is made of a radioactive ray shielding material, said cartridge body ( 8, 18, 38 ) being exposable with said sliding of said shielding outer tube.

This is a division of Application Ser. No. 10/013,366, now U.S. Pat. No.6,723,037.

This application claims a priority based on Japanese Patent ApplicationNo.2000-381529 filed on Dec. 15, 2000 and No.2001-221182 filed on Jul.23, 2001, the entire contents of which are incorporated herein byreference for all purposes.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to improvements in therapeutic materialdelivery device (vehicle) for delivering (implanting) a therapeuticmaterial such as a coiled or capsulated radioactive source to anorganism for radiotherapy, for example, of a patient suffering prostatecancer.

2. Description of the Related Art

Radiotherapy (brachytherapy) refers to a treatment made by allowing aradioactive beam to radiate to a morbid tissue suffering a prostatecancer, an esophagus cancer, or the like. Radiotherapy includeshigh-dose, external beam radiation treatment and low-dose close-distanceradiation treatment.

It is present practice to employ the latter method as a method forimproving a therapeutical effect depending upon a therapeutic site andreducing side effects. In this case, there is practiced a method inwhich a radioactive source having radioactivity in the form of a sealedradioactive source is implanted (caused to remain) in a diseased part ora part near a morbid part with a delivery needle for the radioactivesource, to treat the diseased part. The present invention is applied tothe above method using the sealed radioactive source. The radioactivesource for use in the present invention is selected from thosecontaining radioactive isotopes that are clinically utilizable, andexamples thereof include isotopes of cobalt, phosphorus, strontium,cesium, palladium, yttrium, iridium, rhenium, etc. Particularlypreferred are isotopes that radiate β rays.

The above delivery needle is constituted of an inner needle memberhaving a tubular needle and an outer needle member having a stickingneedle formed to have a sharpened forward end, and a plurality of thecapsular radioactive sources having radioactivity and having a size ofapproximately 5 mm are charged into the above outer needle member withtweezers. The above radioactive sources are spaced with spacers formedof a biodegradable substance, and a wax is applied to the forward end ofthe above sticking needle, so that the above radioactive sources do notcome off the sticking needle.

When capsular radioactive sources are implanted in a diseased part witha delivery needle having the above sticking needle, approximately fiveradioactive sources are charged into one sticking needle as describedabove and are linearly implanted in the diseased part. In this manner,approximately 25 sticking needles above (corresponding to 125radioactive sources) are embedded in different implantation positions.In the implantation, the implantation positions are secured whilemonitoring the positions with an ultrasonic diagnosis apparatus, so thatthe diseased part is uniformly irradiated with the radioactive sources.

Coiled radioactive sources formed by coiling rod-like or wire-likeradioactive sources are recently used in place of capsular radioactivesources. That is because the coiled radioactive sources have a largesurface area each and the length of the radioactive sources per piececan be increased as compared with the capsular radioactive sources, sothat the number of the radioactive sources required can be decreased.The coiled radioactive sources are therefore less frequently chargedinto the outer needle member as compared with the capsular radioactivesources. Further, there is the merit of being free from spots that arenot irradiated with a radioactive ray (cold spots), since it is notrequired to insert the spacers.

However, when a conventional inner needle member having a tubular needleand a conventional outer needle member having a sticking needle, whichare used for implanting capsular radioactive sources, are used forimplanting coiled radioactive sources in a diseased part, the coiledradioactive sources come to be curved, so that the irradiation with auniform dose of radioactive ray can be no longer possible.

It is therefore required to prepare a medical sticking needle having athree-layered structure formed of an inner needle member through whichcoiled radioactive sources are to be passed or generally an inner needlemember for holding a therapeutic material such as radioactive sourcesand extruding them forward, a middle needle member for fixing theradioactive sources and an outer needle member that is to be insertedinto a diseased part or an intended portion, that is, a therapeuticmaterial delivery device. The present invention relates to improvementsin the above delivery device for delivering a therapeutic material suchas radioactive sources.

Further, the delivery device may be a therapeutic material deliverydevice that is formed of an inner needle member for holding atherapeutic material such as radioactive sources and extruding themforward, a cartridge chargeable with the therapeutic material and anouter needle member that is to be inserted into a diseased part or anintended portion. The present invention also relates to improvements insuch a delivery device using said cartridge.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a protective toolfor a therapeutic material delivery device, which is for preventingwrong or accidental sticking of the outer needle after use and forpreventing dissipation of blood adhering to the outer needle, and adelivery device having the tool.

It is another object of the present invention to provide a cartridge foruse with a therapeutic material delivery device, which cartridge permitsdirect calibration of a radioactive source charged therein, and adelivery device having the cartridge.

It is still another object of the present invention to provide acartridge for use with a therapeutic material delivery device, whichcartridge is free from easy breakage of a connector tube connected to anouter needle of the delivery device, and a delivery device having thecartridge.

It is yet another object of the present invention to provide a cartridgefor a therapeutic material delivery device, which cartridge permitsextrusion of charged radioactive sources to the forward end of an outerneedle without any resistance, and a delivery device having thecartridge.

It is further another object of the present invention to provide acartridge for use with a therapeutic material delivery device, whichcartridge permits calibration of the length of radioactive sourcescharged therein by easy external reading, and a delivery device havingthe cartridge.

Still further other objects of the present invention will be clear bydescriptions to be made hereinafter.

According to the present invention, (1) there is provided a protectivetool 68A or 68B for a therapeutic material delivery device comprising anouter needle 2 having an outer tubular needle 2A and an outer needle hub2B supporting the outer tubular needle 2A, the protective tool being tobe attached to said outer needle 2 for the protection thereof,

the protective tool comprising a cover 8′A and a cap 61 or stopper 65attached to a forward end of said cover for protecting the forward endof the outer tubular needle 2A,

wherein said cover 8′A is formed of a plurality of tubes 8′A1, 8′A2,8′A3, . . . having different diameters that are formed so as toconsecutively decrease from a forward place to the outer needle hub 2Bin a backward place, and said tubes are thereby connected such that thecover 8′A is extendable in the longitudinal direction.

According to the present invention, further, (2) there is provided aprotective tool 68A for a therapeutic material delivery device asrecited in the above (1), wherein said cap 61 has an inner tube 61Aformed inside, said inner tube 61A has, made in a bottom thereof, a hole62 for inserting and passing said outer tubular needle 2A, and saidinner tube 61A has, formed in an outer circumference, a groove portion63 for inserting a forward end of said outer tubular needle.

According to the present invention, further, (3) there is provided aprotective tool 68B for a therapeutic material delivery device asrecited in (1), wherein said stopper 65 is constituted of a tubularopening/closing portion 66 having a forward end and a connector portion70,

said opening/closing portion 66 has slits 71 formed in the longitudinaldirection, one in an upper portion and the other in a lower portion,said forward end has an opening portion 66 a, and said connector portion70 has pressing portions 67 formed, one on the right and the other onthe left, and has cutout grooves 69 formed, one in an upper place andthe other in a lower place.

According to the present invention, further, (4) there is provided aprotective tool 68A or 68B for a therapeutic material delivery devicecomprising an outer needle 2 having an outer tubular needle 2A and anouter needle hub 2B supporting the outer tubular needle 2A, a middleneedle 3 having a middle tubular needle 3A and a middle needle hub 3Bsupporting the middle tubular needle 3A and an inner needle 4 having asolid needle 4A and an inner needle hub 4B supporting the solid needle4A, the outer needle, the middle needle and the inner needle being to beconnected for use, the protective tool being to be attached to saidouter needle 2 for the protection thereof,

which protective tool comprises a cover 8′A and a cap 61 or a stopper 65that is attached to the forward end of said cover for protecting theforward end of said outer tubular needle 2A,

wherein said cover 8′A is formed of a plurality of tubes 8′A1, 8′A2,8′A3, . . . having different diameters that are formed so as toconsecutively decrease from a forward place to the outer needle hub 2Bin a backward place, and said tubes are thereby connected such that thecover 8′A is extendable in the longitudinal direction.

According to the present invention, further, (5) there is provided aprotective tool 68A for a therapeutic material delivery device asrecited in (4), wherein said cap 61 has an inner tube 61A formed inside,said inner tube has, in a bottom thereof, a hole 62 for inserting andpassing said outer tubular needle 2A, and said inner tube 61A has,formed in an outer circumference thereof, a groove portion for insertingthe forward end of said outer tubular needle 2A.

According to the present invention, further, (6) there is provided aprotective tool 68B for a therapeutic material delivery device asrecited in (4), wherein said stopper 65 is constituted of a tubularopening/closing portion 66 having a forward end and a connector portion70,

said opening/closing portion 66 has slits 71 formed in the longitudinaldirection, one in an upper portion and the other in a lower portion,said forward end has an opening portion 66 a, and said connector portion70 has pressing portions 67 formed, one on the right and the other onthe left, and has cutout grooves 69 formed, one in an upper place andthe other in a lower place.

According to the present invention, further, (7) there is provided atherapeutic material delivery device 1A or 1B comprising an outer needle2 having an outer tubular needle 2A and an outer needle hub 2Bsupporting the outer tubular needle 2A, wherein said outer needle 2 iscovered with the protective tool 68A or 68B for a therapeutic materialdelivery device as recited in any one of (1) to (3), and the forward endof said outer tubular need 2A of said outer needle 2 is capped with asheath 5′ for protecting said forward end.

According to the present invention, further, (8) there is provided atherapeutic material delivery device 1A or 1B as recited in (7) whereinsaid sheath 5′ has a projection 6′ formed on an inner-circumference baseportion thereof.

According to the present invention, further, (9) there is provided atherapeutic material delivery device 1A or 1B comprising an outer needle2 having an outer tubular needle 2A and an outer needle hub 2Bsupporting the outer tubular needle 2A, a middle needle 3 having amiddle tubular needle 3A and a middle needle hub 3B supporting themiddle tubular needle 3A and an inner needle 4 having a solid needle 4Aand an inner needle hub 4B supporting the solid needle 4A, said outerneedle 2, said middle needle 3 and said inner needle 4 being to beconnected in this order for use,

wherein the protective tool 68A or 68B for a therapeutic materialdelivery device as recited in any one of (4) to (6) is attached to saidouter needle 2.

According to the present invention, further, (10) there is provided atherapeutic material delivery device 1A or 1B as recited in (9), whereinsaid solid needle 4A is inserted in said middle tubular needle 3A, saidmiddle tubular needle 3A is inserted in said outer tubular needle 2A andthe forward end of said outer tubular needle 2A is capped with a sheath5′ for protection of said forward end.

According to the present invention, further, (11), there is provided atherapeutic material delivery device 1A or 1B as recited in (9) or (10),wherein said outer tubular needle 2A, said middle tubular needle 3A andsaid solid needle 4A are formed such that said solid needle 4A has alargest length, that said middle tubular needle 3A has an intermediatelength and that said outer tubular needle 2A has a smallest length.

According to the present invention, further, (12) there is provided atherapeutic material delivery device 1A or 1B comprising a outer needle2 having an outer tubular needle 2A and an outer needle hub 2Bsupporting the outer tubular needle 2A, a middle needle 3 having amiddle tubular needle 3A and a middle needle hub 3B supporting themiddle tubular needle 3A and an inner needle 4 having a solid needle 4Aand an inner needle hub 4B supporting the solid needle 4A,

wherein said outer needle 2, said middle needle 3 and said inner needle4 are being to be connected for use.

According to the present invention, further, (13) there is provided atherapeutic material delivery device 1A or 1B as recited in (12),wherein the forward end of the outer tubular needle 2A of said outerneedle 2 is capped with a sheath 5′ for protection of said forward end.

According to the present invention, further, (14) there is provided atherapeutic material delivery device 1A or 1B as recited in (13),wherein said sheath 5′ has a projection 6′ formed on an innercircumference base portion thereof.

According to the present invention, further, (15) there is provided atherapeutic material delivery device 1A or 1B as recited in (12),wherein said outer tubular needle 2A, said middle tubular needle 3A andsaid solid needle 4A are formed such that said solid needle 4A has alargest length, that said middle tubular needle 3A has an intermediatelength and that said outer tubular needle 2A has a smallest length.

According to the present invention, further, (16) there is provided acartridge 7,17 or 37 for a therapeutic material delivery device, whichcartridge permits external visual observation of the therapeuticmaterial, the cartridge comprising a transparent cartridge body 8, 18 or38 that holds said therapeutic material 10 inside and permits externalvisual observation of the therapeutic material 10 and a shielding outertube 9, 19 or 39 that is fitted on an outer circumference of thecartridge body, is slidable in the longitudinal direction of saidcartridge body and is made of a radioactive ray shielding material, saidcartridge body 8, 18 or 38 being exposable with said sliding of saidshielding outer tube.

According to the present invention, further, (17) there is provided acartridge 7 or 17 for a therapeutic material delivery device as recitedin (16), wherein the forward end of said cartridge body 8 or 18 isprovided with a head portion 5 or 5A, a connector tube 6 is supportedthrough said head portion, and said connector tube 6 is capped with asheath 12 having an opening portion 12A formed therein.

According to the present invention, further, (18) there is provided acartridge 37 for a therapeutic material delivery device as recited in(16), wherein the forward end of said cartridge body 38 is provided witha head portion 5E, a connector tube 36 is supported through said headportion and said connector tube 36 is capped with a cap C1 having aprotection portion 21 and a spindle rod 22 supported on a centralportion of inner circumference end portion of the protection portion 21.

According to the present invention, further, (19) there is provided acartridge 7 or 37 for a therapeutic material delivery device as recitedin any one of (16) to (18), wherein an engagement portion 5C or 35C isformed in the backward end of the head portion 5 or 5E provided in theforward end of said cartridge 7 or 37, an engagement portion 9A or 38Ais formed in the forward end of said outer tube 9 or 39, and theseengagement portions are engageable with each other.

According to the present invention, further, (20) there is provided acartridge 7, 17 or 37 for a therapeutic material delivery device asrecited in any one of (16) to (19), wherein a stopper 16 is attached tonearly a central portion of said head portion 5, 5A or 5E of saidcartridge body 8, 18 or 38, and said cartridge body and said outer tubeare engageable with each other on the basis of a frictional resistancebetween said stopper 16 and an inner circumference of forward end ofsaid outer tube 9, 19 or 39.

According to the present invention, further, (21) there is provided acartridge 7 or 17 for a therapeutic material delivery device as recitedin any one of (16), (17), (19) and (20), wherein an outer circumferencesurface of said cartridge body 8 or 18 is provided with a scale 20 forchecking a length or an amount of the therapeutic material 10 chargedinside said cartridge body 8 or 18.

According to the present invention, further, (22) there is provided acartridge 37 for a therapeutic material delivery device as recited inany one of (16), (18), (19) and (20), wherein an outer circumferencesurface of said cartridge body 38 is provided with a scale 30 havingdivisions starting at 0 cm at intervals of 1 cm for checking a length ofthe therapeutic material 10 charged in said cartridge body 38 and forcalibration of the entire therapeutic material 10.

According to the present invention, further, (23) there is provided acartridge 27 for a therapeutic material delivery device, which cartridgehas a cartridge body 28 that permits external visual observation of atherapeutic material 10 held therein, wherein said cartridge body 28 isformed of material that can work as a shield against radioactive raysand has a scale 20 provided on an outer circumference of said cartridgebody 28, the forward end of said cartridge body 28 has a head portion5B, a connector tube 6 is supported through said head portion, and saidconnector tube 6 is capped with a sheath 12 having an opening portion12A formed therein.

According to the present invention, further, (24) there is provided atherapeutic material delivery device 1 comprising an outer needle 2 or32 having an outer tubular needle 2A or 32A and an outer needle hub 2Bor 32B supporting the outer tubular needle 2A or 32A, the cartridge 7,17, 27, 37 for a therapeutic material delivery device as recited in anyone of (16) to (23) which cartridge is chargeable with a therapeuticmaterial 10 and an inner needle 4 having a solid needle 4A and an innerneedle hub 4B supporting the solid needle 4A,

wherein an inner circumference of said outer needle hub 2B or 32B andthe forward end portion of said cartridge 7, 17, 27 or 37 are formed tohave mutually engageable forms,

the therapeutic material delivery device 1 having a constitution inwhich said solid needle 4A is inserted through the backward end of saidcartridge 7, 17, 27 or 37 thereby to extrude said therapeutic material10 into said tubular needle 2A or 32A with the forward end of said solidneedle 4A.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic drawing of one example of the therapeutic materialdelivery device 1 of the present invention.

FIGS. 2( a), 2(b) and 2(c) are exploded views of the therapeuticmaterial delivery device shown in FIG. 1; FIG. 2( a) is a schematicdrawing of an outer needle 2, FIG. 2( b) is a schematic drawing of amiddle needle, and FIG. 2( c) is a schematic drawing of an inner needle.

FIG. 3 is a schematic partial exploded drawing of a sheath 5′.

FIG. 4 is a schematic drawing of a delivery device 1A in which a forwardend cover 64 is attached to a protective tool 68A.

FIG. 5 is a cross-sectional view of a cap 61.

FIGS. 6( a), 6(b), 6(c) and 6(d) are schematic drawings for showing howto use the protective tool 68A attached to the delivery device 1A inFIG. 4.

FIG. 7 is a schematic drawing of a delivery device 1B in which a sheath5′ is attached to a protective tool 68B.

FIGS. 8( a) and 8(b) are schematic drawings of a stopper 65; FIG. 8( a)is a front view, and FIG. 8( b) is a plan view.

FIGS. 9( a), 9(b) and 9(c) are schematic drawings for showing how to usethe protective tool 68B attached to the delivery device 1B in FIG. 7.

FIG. 10 is a schematic drawing of a therapeutic material delivery device1′ of the present invention.

FIG. 11 is a cross-sectional view of a cartridge 7 of the presentinvention.

FIGS. 12(A), 12(B) and 12(C) are schematic drawings of components of thecartridge shown in FIG. 11; FIG. 12(A) is a side view of forward end ofan outer tube 9, FIG. 12(B) are a cross-sectional view of the outer tube9 in the longitudinal direction, and FIG. 12(C) is a schematic drawingof a cartridge body 8.

FIG. 13 is a schematic drawing for showing a state in which the outertube 9 of the cartridge 7 is slid backward in the longitudinal directionand the cartridge body 8 is exposed.

FIG. 14 is a cross-sectional view of a cartridge 17 that is anotherembodiment of the cartridge.

FIG. 15 is a schematic drawing for showing a state in which the outertube 19 of the cartridge 17 is slid backward in the longitudinaldirection and a cartridge body 18 is exposed.

FIG. 16 is a cross-sectional view of a cartridge 27 that is anotherembodiment of the cartridge.

FIG. 17 is a schematic drawing of a cap C1.

FIG. 18 is a cross-sectional view of a cartridge 37 of the presentinvention to which the cap C1 is attached.

FIG. 19 is a schematic drawing for showing a state in which an outertube 39 of the cartridge 37 is slid backward in the longitudinaldirection and a cartridge body 38 is exposed.

FIG. 20 shows schematic drawings for explaining procedures of embeddingradioactive sources 10 in the interior of a body with a delivery deviceusing the cartridge 17 of the present invention.

FIG. 21 shows schematic drawings for explaining procedures of embeddingradioactive sources 10 in the interior of a body with a delivery deviceusing the cartridge 37 of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be explained in detail hereinafter.

(Therapeutic Material Delivery Device)

The “therapeutic material” in the present invention refers to atumor-treating material against tumors such as cancers. The protectivetool for a therapeutic material delivery device, provided by the presentinvention, is a tool that is used with a therapeutic material deliverydevice. The therapeutic material delivery device may be adouble-layer-structured delivery device having at least an outer needle2 formed of an outer tubular needle 2A and an outer needle hub 2Bsupporting the outer tubular needle 2A, and an inner needle 4 formed ofa solid needle 4A and an inner needle hub 4B supporting the solid needle4A as shown in part of FIG. 1. Preferably, the therapeutic materialdelivery device is a three-layer-structured therapeutic materialdelivery device 1 having an outer needle 2 formed of an outer tubularneedle 2A and an outer needle hub 2B supporting the outer tubular needle2A, a middle needle 3 formed of a middle tubular needle 3A and a middleneedle hub supporting the middle tubular needle 3A and an inner needle 4formed of a solid needle 4A and an inner needle hub 4B supporting thesolid needle 4A as is shown in the entire drawing of FIG. 1. And, theouter needle 2, the middle needle 3 and the inner needle 4 are connectedin this order when used.

(Outer Needle and Sheath 5′)

The therapeutic material delivery device 1 (to be sometimes abbreviatedas “delivery device 1” hereinafter) of the present invention has atleast an outer needle 2 formed of an outer tubular needle 2A and anouter needle hub 2B supporting the outer tubular needle 2A. The outertubular needle 2A of the outer needle 2 is preferably made of a metalsuch as SUS304, SUS316, or the like, and the forward end portion thereofis formed so as to have a sharpened end for sticking it into a humanbody. The forward end of the above outer tubular needle 2A of the outerneedle 2 is covered with a sheath 5′. The sheath 5′ is provided forprotecting the sharp forward end of the outer tubular needle 2A. Thatis, when the forward end of the outer tubular needle 2A of the deliverydevice is capped with the sheath 5′, the sheath 5′ can prevent a bending(curling) of the forward end of the outer tubular needle 2A whichbending (curling) may be caused by a contact of the forward end to asurface of a storage box or a delivery plate to be described later.Preferably, the sheath 5′ is made of an elastic material. For example,the elastic material includes synthetic rubbers such as isoprene rubber,chloroprene rubber, acryl rubber, silicone rubber and nitrile rubber;and synthetic resins such as polyolefin resins, polyurethane resins,polyester resins and polyvinyl chloride rubbers, which are thermoplasticelastomers. Preferably, a projection 6′ is formed on a base part ofinner circumference of the sheath 5′ as shown in FIG. 3. The aboveprojection 6′ is formed for contact-fixing the projection 6′ to theouter circumferential wall of the above outer tubular needle 2A, so thatthe covering sheath 5′ does not easily come off the outer tubular needle2A.

The above outer needle 2, the middle needle 3 and the inner needle 4 areconnected in this order when used. Specifically, the solid needle 4A ofthe inner needle 4 is inserted into, and positioned in, the above middletubular needle 3A, and the above middle needle 4 is inserted into, andpositioned in, the outer tubular needle 2A of the above outer needle 4.

(Outer Tubular Needle Marker)

Preferably, the outer circumference of the above outer tubular needle 2Ahas markers 9′ that are provided equivalently as indices for a length ofinsertion of the outer tubular needle 4 into a diseased part orwithdrawal thereof from the diseased part, as is shown in FIG. 1.Preferably, for example, dented portions 11′ are formed in the outercircumference of the outer needle hub 2B, so that an operator easilymanually handles the delivery device. Further, preferably, a marker 10′is provided on the outer circumference of the outer needle hub 2B forindicating the direction of edge surface of the forward end of the aboveouter tubular needle 2A as shown in FIG. 2( a).

(Middle Needle)

Like the above outer needle hub 2A, the middle tubular needle 3A of themiddle needle 3 is made of a metal such as SUS304, 316, or the like, andit has the form of a tube and the forward end thereof is formed to beflat as shown in FIG. 2( b). Once a radioactive source 7, is arrangedaround the forward circumference of the above solid needle 4A, thebackward movement of the radioactive source 7′ can be prevented sincethe forward end of the above middle tubular needle 3A is present.

On the outer circumference of each of the middle tubular needle 3A andthe inner needle 4A, further, markers 9′A (or 9′B) are provided at equalintervals as shown in FIGS. 2( b) or 2(c). The markers 9′A on the middletubular needle 3A indicate positions of the forward end of the middleneedle 3 when it is inserted into the outer needle 2. Further, themarkers 9′B on the inner needle 4A can work as an index for aligning theforward end of the radioactive source 7′ and the forward end of theinner needle 4 by longitudinally moving the above inner needle 4.

The above markers 9′A (and 9′B) can be provided on the abovecircumferences so that the number of the markers shows an actual length,like, for example, 1 cm shown by one marker or 2 cm shown by twomarkers.

(Inner Needle)

The solid needle 4A of the inner needle 4 is generally made of a metalsuch as SUS304, 316, or the like, and is formed to have the form of afine wire. While the solid needle 4A preferably has the form of a wire,it may be a so-called tubular pin (sometimes referred to as “pipe-shapedpin” hereinafter) having a hollow portion inside, so long as the solidneedle 4A can fit (the term “insert” is sometimes used hereinafter) theradioactive source 7 to the forward end of the outer circumference orextrude a capsulated radioactive source charged inside the outer needlefrom the outer needle so that the radioactive source can be implanted inan intended part in a human body. The solid needle 4A in the presentinvention therefore includes both a solid needle having the form of awire and a solid needle having the form of a tube.

(Assembly of Delivery Device)

The delivery device 1 of the present invention has a form shown in FIG.1, and for example, it is assembled as follows. First, the above solidneedle 4A is inserted into, and positioned in, the above middle tubularneedle 3A through the above middle needle hub 3B. Further, the abovemiddle tubular needle 3A is inserted into, and positioned in, the aboveouter tubular needle 2A through the above outer needle hub 2B, toassemble the delivery device 1 having a three-layer structure. In theabove three-layer-structured delivery device, the sheath 5′ is fitted onthe forward end of the outer needle 2, and a cover 8′ as a protectivetool (to be described later) for the delivery device is fitted to theabove outer tubular needle 2A, for the protection of the deliverydevice.

In the present invention, in compliance with the constitution of theabove three-layer-structured delivery device, the above outer tubularneedle 2A, the above middle tubular needle 3A and the above solid needle4A are formed such that the solid needle 4A has a largest length, thatthe middle tubular needle 3A has an intermediate length and that theouter tubular needle 2A has a smallest length, as shown in FIGS. 2( a),2(b) and 2(c).

In the present invention, when the coil-shaped radioactive source 7′ isimplanted in a diseased part or an intended part, the coil-shapedradioactive source 7′ can be linearly implanted without curving thecoil-shaped radioactive source 7′, owning to the use of the deliverydevice 1 formed of the inner needle 4, the middle needle 3 and the outerneedle 2 in which the solid needle 4A having a largest length, themiddle tubular needle 3A having an intermediate length and the outertubular needle 2A having a smallest length are arranged in this order.

In this case, when the middle needle 3 is inserted into the outer needle2 thereby to align the middle needle hub 3B of the middle needle 3 andthe outer needle hub 2B of the outer needle 2, preferably, the middletubular needle 3A of the middle needle 3 is exposed from the edgesurface of the outer tubular needle 2A of the outer needle 2 to someextent. That is because the radioactive source 7′ charged in the solidneedle 4A of the inner needle 4 can be completely exposed from theforward end of the outer tubular needle 2A of the above outer needle 2.If the forward end of the middle tubular needle 3A of the middle needle3 is not exposed from the edge surface of the outer tubular needle 2A ofthe outer needle 2, the backward portion of the radioactive source 7′may be caught inside the outer tubular needle 2A of the outer needle 2,so that it may be difficult to conduct an implanting operation.

The solid needle 4A of the inner needle 4 is required to have a lengththat is equivalent approximately to at least the total length of themiddle needle 3 and the radioactive source 7′ for exposing theradioactive source 7′ from the forward end of the outer tubular needle2A of the above outer needle 2, so that the solid needle 4A has thelargest length among the above three needle types.

(Method of Using Delivery Device)

A typical example of the method of use of the delivery device 1 of thepresent invention for low-dose radiation treatment will be explainedbelow.

(1) The middle needle 3 and the inner needle 4 are integrally withdrawnfrom the outer needle 2 of the delivery device 1 shown in FIG. 1.

(2) In this case, the solid needle 4A of the inner needle 4 is exposedfrom the middle tubular needle 3A of the middle needle 3.

(3) The coil-shaped radioactive source 7′ is charged around the forwardend of the solid needle 4A in the above (2). In other words, the forwardend portion of the solid needle 4A is inserted into the coil-shapedradioactive source 7′.

(4) After it is made certain that the above solid needle 4A is keptinserted through the radioactive source 7′, the middle needle 3 and theinner needle 4 are integrally inserted into the outer needle 2 cappedwith the sheath 5′, and the insertion is continued until the forward endof the above solid needle 4A comes in contact with the sheath 5′.

(5) The delivery device 1 charged with the radioactive source 7 isstored in a storage box (not shown) without a cover 8′. The storage boxis a container that has holes which are arranged in width andlongitudinal directions and into which delivery devices 1 are regularlyinserted, and the container is used for temporary storage of thedelivery devices before sticking needles of the delivery devices chargedwith the radioactive source each are inserted to diseased parts ofpatients.

(6) When the radioactive source 7′ is stuck into a diseased part or anintended portion, generally, radioactive sources are implanted with aplate (not shown) having sticking holes arranged regularly in thelongitudinal and width directions. The outer needles 2 of the deliverydevices 1 taken out of the storage box are stuck in the sticking holes(intended positions) of the plate that determines implantationpositions. The outer needle 2 brakes through the sheath 5′ to reach anintended portion of a patient. In this case, preferably, implantationpositions are checked with monitoring them with an ultrasonic diagnosisapparatus inserted through an anus in the same manner as in theimplantation positioning of a conventional capsulated radioactivesource.

(7) After the implantation positions are determined, the middle needlehub 3B of the middle needle 3 of the delivery device 1 is fixed to bestill, and the outer needle 2 is withdrawn backward, whereby theradioactive source 7′ charged in the solid needle 4A of the inner needle4 is exposed inside a body.

(8) The middle needle hub 3B of the middle is fixed to be still, and theinner needle hub 4B of the inner needle 4 is withdrawn, whereby theradioactive source 7′ is linearly implanted in an intended portion inthe body.

(9) The outer needle 2 and the middle needle 3 are withdrawn at the sametime, to complete the implantation of the radioactive source 7′.

While the three-layer-structured delivery device 1 having the forwardend of the outer tubular needle 2A capped with the sheath 5′ has beenexplained above with reference to its use example, a delivery devicehaving the outer needle charged with a conventional capsulatedradioactive source (delivery device having an outer needle formed of anouter tubular needle and an outer needle hub supporting the outertubular needle) having the forward end of the outer needle 2 capped withthe sheath 5′ can be similarly used.

(Protective Tool for Therapeutic Material Delivery Device and Method ofUse Thereof)

FIG. 4 is a schematic drawing of a delivery device 1A to which aprotective tool 68A for a therapeutic material delivery device (to besometimes abbreviated as “protective tool 68A” hereinafter) is fitted,provided by the present invention. FIG. 5 is a cross-sectional view of acap 61 for use as an element of the protective tool. The aboveprotective tool can be applied both to the three-layer-structureddelivery device and the delivery device having the inner needle and theouter needle and having a capsulated radioactive source charged in theouter needle.

The above protective tool 68A is constituted of a cover 8′ for coveringthe outer tubular needle 2A and a cap 61. Preferably, the forward end ofthe outer tubular needle 2A is covered with a pipe-shaped forward endcover 64 for protecting the needle end before use.

The above cover 8′ is formed of a plurality of tubes having differentdiameters (8′A1, 8′A2, 8′A3, . . . , 8′An) as shown in FIG. 4. In orderto make a good connection with the cap 61 and forward end cover 64 andallow a smooth move forward of the outer tubular needles 2A, the tubesare formed such that the diameters thereof consecutively decrease from aforward place to the outer needle hub in a backward place (8′An> . . .>8′A3>8′A2>8′A1), whereby the tubes are connected in such a manner thatthe tubes are extended and shrunk (folded) in the longitudinal directionof the tubes. In addition, n represents the number of the tubes, and aproper number can be selected depending upon the length of the outertubular needle 2A. It is not excluded that if necessary the diameters ofthe tubes may be constructed in the opposite mode as described above(8′An< . . . <8′A3<8′A2<8′A1).

When the above cover 8′A is used to cover the outer tubular needle 2A,the innermost tube (8′A in this case) having the smallest diameter isfitted to the outer needle hub 2B of the outer needle 2 and the cover 8′is extended in the direction of the needle forward end. In this manner,there is formed a tube that changes stage by stage from a smallest tubemember to a largest tube member. FIG. 4 shows a state of the thus-formedmulti-stage tube, for example, a six-staged tube (tube members 8′A1,8′A2, 8′A3, 8′A4, 8′A5 and 8′A6) covering the outer tubular needle 2A.

Further, the forward end of the above cover 8′A is capped with a cap 61.As shown in FIG. 5, the above cap 61 has an inner passage 61A formedinside, and a bottom of the inner passage 61A has a hole for passing theabove outer tubular needle 2A through it. Further, a circumference ofthe inner passage 61A has a groove 63 for inserting the above outertubular needle 2A therein for rest.

FIG. 6 shows one example showing how to use the delivery device 1 towhich the protective tool 68A having the cap 61 in its forward end isattached. The method of using the delivery device 1 will be explainedwith reference to FIG. 6 hereinafter.

(1) The forward end cover 64 attached to the above delivery device 1A isremoved (FIG. 6( a)).

(2) The cap 61 and the cover 8′ are pushed toward the outer needle hub2B to fold the cover 8′A and to expose the outer tubular needle 2A (FIG.6( b)).

(3) The radioactive source 7′ is implanted in an intended portion in abody with the delivery device according to the already explained method.

(4) After the use of the delivery device (after completion of theimplantation of the radioactive source), the above cover 8′A is extendedto encase the forward end of the outer tubular needle 2A in the cap 61(FIG. 6( c)).

(5) The outer-circumferential portion of the outer tubular needle 2A isbrought into contact with the cap 61 and the inner circumference (innerwall) of the cover 8′A, and then the above cover 8′A is pushed towardthe outer needle hub 2B, to insert the forward end of the outer tubularneedle 2A in the groove 63 of the above cap 61 for rest.

The protective tool 68A is covered on the outer needle 2 as describedabove, whereby wrong or accidental sticking with the used outer tubularneedle 2A and dissipation of adhering blood can be prevented.

(Other Embodiment of the Protective Tool)

FIG. 7 is a schematic drawing of a delivery device 1B using a protectivetool 68B for a therapeutic material delivery device (to be sometimesreferred to as “protective tool 68B” hereinafter) which protective toolis other embodiment of the present invention different from the aboveprotective tool 68A (FIG. 4).

FIG. 7 shows the delivery device 1B to which the protective tool 68B andthe sheath 5′ are attached. The delivery device 1B can be applied toboth a three-layer-structured delivery device and a delivery devicehaving an inner needle and an outer needle and having a capsulatedradioactive source charged in the outer needle. FIGS. 8( a) and 8(b) areschematic drawings of a stopper 65; FIG. 8( a) is a front view, and FIG.8( b) is a plan view.

The above protective tool 68B is constituted of the above cover 8′A anda stopper 65, and the forward end of the above stopper 8′A is cappedwith the stopper 65. The above stopper is arranged such that a slit 71and a cutout groove 69 to be described later are positioned above andbelow.

In the above stopper 65, a tubular opening/closing portion 66 having aforward end and a connector portion 70 are integrally formed.

In the above opening/closing portion 66, slits 71 are formed in thelongitudinal direction, one in an upper portion and the other in a lowerportion. As shown in FIG. 8( a), further, an opening portion 66 acommunicating with the slits 71 and having the form, for example, of acircle is formed in the above forward end portion. Further, in abackward place of the above slits 71, a hole 72 having the form, forexample, of a circle and communicating with the slits 71 is formed (FIG.8( a)). While the above slits 71 may have a slight width each, the slits71 may be a parting cut. In the above connector portion 70, pressingportions 67 are formed, one on the right and the other on the left, andcutout grooves 69 are formed, one in an upper place and the other in alower place. The stopper 65 is fitted to the forward end of the cover8′A such that the slits 71 and the cutout grooves 69 are positioned oneeach top and bottom. When the above pressing portions 67 are held withfingers and pressed toward each other, the opening/closing portion 66opens fanwise along the slits 71 from the hole 72 as a center, wherebythe above opening portion 66 a also opens leftward and rightward. Whenthe pressing force is decreased, the above opening/closing portion 66closes, and at the same time, the above opening portion 66 a alsocloses.

Further, as shown in FIG. 7, the forward end of the outer tubular needle2A is capped with the sheath 5′, and the outer circumference of theabove sheath 5′ is held between opening portions 66 a of theopening/closing portion 66 of the above stopper, so that the sheath 5′does not come off the forward end of the outer tubular needle 2A.

FIG. 9 shows one example of the method of use of the delivery device 1Bto which the protective tool 68B having the stopper 65 in its forwardend is attached. The method of use will be explained with reference toFIG. 9 hereinafter.

(1) As shown in FIG. 7, the sheath 5′ is held between the openingportions 66 a of the stopper 65 during the storage of the deliverydevice. In this state, the pressing portions 67 of the above stopper 65are pressed with fingers to open the opening/closing portion 66, and theouter circumference of the sheath 5′ is removed from the openingportions 66 a. The above cover 8′A is folded toward the outer needle hub2B to expose the outer tubular needle 2A (FIG. 9( a)).

(2) The radioactive source 7′ is implanted in an intended portion in abody with the delivery device 1B according to the already explainedmethod.

(3) After the delivery device is used (after the implantation of theradioactive source is completed), the sheath 5′ is moved to have aposition nearly in a central portion of the tubular needle 2A (FIG. 9(b)).

(4) The stopper 65 and the cover 8′A are moved toward the forward end ofthe tubular needle 2A, and the above sheath 5′ is removed from the outertubular needle 2A to place the forward end of the outer tubular needle2A in the opening/closing portion 66 of the stopper 65 (FIG. 9( c)).

In this manner, as shown in the above-referenced FIG. 9( c), the outertubular needle 2A encased in the protective tool 68B has only one endsupported with the outer needle hub and the other end (forward end) isnot supported, so that the outer tubular needle 2A bends due to its ownweight to have its forward end portion coming close to the inner wall ofthe above protective tool 68B. In this manner, there is no case wherethe forward end of the above outer tubular needle 2A is exposed from theopening portions 66 a of the stopper 65.

When the protective tool 68B is used to cover the outer needle 2 asdescribed above, therefore, wrong or accidental sticking with the usedouter tubular needle 2A and dissipation of adhering blood can beprevented.

The above cover 8′A, the above cap 61 and the above stopper 65 can beformed from a hard plastic such as polycarbonate, polymethylmethacrylate, polypropylene or polyvinyl chloride or an easilyprocessible metal such as stainless steel or aluminum. As explainedabove, the protective tools 68A and 68B for a therapeutic materialdelivery device, provided by the present invention, can be suitablyapplied, for example, to the delivery devices 1, 1A and 1B for delivery(implantation) of the therapeutic material such as a radioactive source.

(Delivery Device Using Transparent Cartridge)

The therapeutic material delivery device may be a therapeutic materialdelivery device that is constructed according to a method somewhatdifferent from the above-explained method. The device comprises an innerneedle for holding a therapeutic material and extruding it forward, atransparent cartridge chargeable with a therapeutic material, and anouter needle to be stuck into a diseased part or an intended portion.

For a basic therapeutic material delivery device using such a cartridge,the present applicants have already filed Japanese Patent ApplicationNo. 2001-068695.

In this case, however, the radiation dose of a radioactive source iscalibrated (checked) before the radioactive source is charged into thecartridge. Therefore, the radioactive source is inevitably calibrated ina state where it is exposed.

Further, since the cartridge has the form of a nearly ellipsoid like apencil cap and is formed of lead glass or a burst-resistant resin, theforward end thereof may be broken when a force is laterally exerted onthe cartridge that is attached to the outer needle hub of the outerneedle.

In the above cartridge, further, the cartridge is stuffed with a fillerin the forward and backward ends so that the charged radioactive sourcedoes not come out. When the amount of the filler is large, the filler isliable to enter the outer needle hub, and if this is case, it isdifficult to extrude the radioactive source to the forward end of theouter tubular needle. According to the present invention, there isprovided a delivery device for use with the above cartridge, whichdelivery device overcomes the problem caused by the use of the abovecartridge.

The delivery device will be explained with reference to drawings.

FIG. 10 is a schematic drawing of one example of a therapeutic materialdelivery device 1′ (to be abbreviated as “delivery device 1′”hereinafter) for delivery of a radioactive source, provided by thepresent invention.

The delivery device 1′ shown in FIG. 10 is constituted of an outerneedle 2 formed of an outer tubular needle 2A and an outer needle hub 2Bsupporting the outer tubular needle 2A, a cartridge 7 chargeable with aradioactive source 10 (see FIG. 11) that is to be connected thereto, andan inner needle 4 formed of a solid needle 4A and an inner needle hub 4Bsupporting the solid needle 4A.

In the above outer needle 2, the outer tubular needle 2A has a forwardend that is sharpened so that it can be stuck into a body, and the endportion of the above outer tubular needle 2A is attached to the outerneedle hub 2B. In the above outer needle hub 2B, preferably, asmall-diameter portion 2B1, an intermediate-diameter portion 2B2 and alarge-diameter portion 2B3 are integrally formed continuously from aforward end place to a backward end place for securing reliableengagement of the outer needle hub 2B with the forward end of thecartridge inserted when the cartridge is connected.

FIG. 11 is a cross-sectional view of a cartridge for use with thetherapeutic material delivery device 1′ shown in FIG. 10 (to be simplyabbreviated as “cartridge” hereinafter), provided by the presentinvention. FIGS. 12(A), 12(B) and 12(C) are schematic drawings ofcomponents of the cartridge 7 shown in FIG. 11; FIG. 12(A) is a sideview of forward end of the above outer tube 9, FIG. 12(B) is across-sectional view of the outer tube 9 in the longitudinal direction,and FIG. 9(C) is a schematic drawing of a cartridge body 8.

The cartridge 7 is constituted of a transparent cartridge body 8 that isfor holding the above therapeutic material 10 inside and permitsexternal visual observation thereof, and a shielding outer tube 9 thatis fitted to the outer circumference of the cartridge body, is slidablein the longitudinal direction of the above cartridge and is made of ashielding material against radioactive rays.

The above shielding outer tube 9 (to be sometimes simply abbreviated as“outer tube 9” hereinafter) is made of a material that works as a shieldagainst radioactive rays, and an engagement portion 9A may be formed inan inner circumference of the forward end thereof.

In the above cartridge body 8, a space 8A for encasing the radioactivesource 10 is formed in a central portion of the cartridge body 8 in thelongitudinal direction. As shown in FIGS. 11 and 12, further, theforward end thereof is provided with a head portion 5, the backward endthereof is provided with a stopper 15, and the backward end of the abovehead portion 5 is provided with an engagement portion 5C that is to beengaged with the engagement portion 9A of the above outer tube 9.

The above head portion 5 supports a connector tube 6 whose forward endis formed in a tapered form, through the head portion, and the connectortube 6 is capped with a sheath 12 having an opening portion 12A having asmaller diameter than the outer diameter of the radioactive source 10 inthe forward end thereof.

Since the above opening portion 12A has a smaller diameter than theouter diameter of the radioactive source, the radioactive source 10 doesnot easily come off the above opening portion 12A, and when the backwardend of the radioactive source 10 is pushed and extruded with the forwardend of the solid needle 4A, the radioactive source 10 can move towardthe forward end of the outer needle 2 through the above opening portion12A. The above sheath 12 is made of a soft material that is the same as,or similar to, that used for the already described sheath 5′.

As described already, the above cartridge body 8 is made of a materialthrough which the radioactive source 10 charged and held inside can bevisually observed from outside.

(Slide/Engagement Between Cartridge Body and Outer Tube)

In the cartridge 7, the outer tube 9 covers a circumference of thecartridge body 8. In this case, the engagement portion 5C of thebackward end of the above head portion 5 and the engagement portion 9Aof the forward end of the outer tube 9 are formed such that theseengagement portions engage with each other. The backward end of thecartridge 7 is capped with a cap C which covers the outer tube 9.

FIG. 13 is a schematic drawing showing a state in which the outer tube 9of the cartridge 7 is turned to slide it backwardly in the longitudinaldirection and the cartridge body 8 is exposed.

When the radioactive source 10 charged in the cartridge body 8 iscalibrated, the outer tube 9 is slid backwardly in the longitudinaldirection to expose the cartridge body 8 (details thereof will bediscussed later with reference to FIG. 15).

As shown in the schematic drawing of FIG. 13, when the outer tube 9 isslid in the longitudinal direction of the cartridge body to expose thecartridge body 8, the engagement portion 9A of the outer tube 9 isengaged with the forward end of the above stopper 15, so that there isno case where the outer tube 9 comes off the cartridge body 8.

FIG. 14 is a cross-sectional view of a cartridge 17 that is otherembodiment of the cartridge. FIG. 15 is a schematic drawing showing astate in which the outer tube 19 of the cartridge 17 is slid to exposethe cartridge body 18.

The above cartridge 17 employs a constitution in which a stopper 16 isattached to the head portion 5A so that an outer tube 19 can be caughtand stopped with the cartridge body 18 in place of forming theengagement portions 9A and 5C used for stopping the outer tube 9 in thecartridge body 8 like the above cartridge 7.

That is, the forward end of the cartridge body 18 is provided with ahead portion 5A, and a stopper 16 having high frictional resistance isattached to a nearly central portion of the above head portion 5A. Thestopper 16 is made of a material having high frictional resistance likeelastomers such as rubber and silicone, and it is formed in the form ofa band or a stripe having a cross-sectional form of a circle, an oval, asquare, or the like. It is not necessarily required to form the stopper16 on the entire outer circumference of the head portion 5A, and it maybe formed at intervals or discontinuously so long as it can ensuresufficient frictional resistance.

Due to the frictional resistance between the above stopper 16 and theinner circumference of the forward end of the outer tube 19, thecartridge body 18 and the outer tube 19 are engaged with each other.

The above outer tube 19 is allowed to slide backwardly in thelongitudinal direction, to expose the cartridge body 18. The surface ofthe inner circumference of forward portion of the outer tube 19 isprovided with an engagement portion 19A similar to the already explainedengagement portion 9A of the outer tube 9, so that the thus-providedengagement portion 19A is caught and stopped with a stopper 25 formed inthe backward end of the cartridge body 18. There is therefore no case inwhich the above outer tube 19 comes off the cartridge body 18.

(Scale Marking and Calibration)

The surface of the cartridge body 18 of the above cartridge 17 isprovided with a scale 20 for check of a length of the radioactive source10. The scale indicates a length from the forward end of the connectortube 6. For example, in a case shown in FIG. 15, a division of 2 cm ismarked on the end portion of the cartridge body 18, and divisions areprovided up to 6 cm at intervals of 1 cm. Similarly, the cartridgebodies 8 and 28 of cartridges 7 and 27 may be provided with a scale.

The calibration of the radioactive source 10 held in the above cartridgebody 18 will be explained with regard to the cartridge 17 as oneexample.

As shown in FIG. 15, the above radioactive source 10 is positioned inthe forward end of the connector tube 6 (position where the forward endof inner circumference of the sheath 12 is hit against), and the outertube 19 is slid backwardly in the longitudinal direction.

When the radioactive source 10 is visually observed through thecartridge body 18 in the above case, and if the backward end of theradioactive source 10 is positioned at a division of 3, it is impliedthat the radioactive source 10 encased has a length of 3 cm. That is,that part of the radioactive source 10 charged in the above cartridge 17which is exposed and externally visually observable in the cartridgebody 18 has a length of only 1 cm. In this state, calibration isconducted, and the above 1 cm long part of the radioactive source isconverted and calculated to the conclusion that the radioactive sourcehaving a radiation dose equivalent to 3 cm is charged.

In addition, the cartridge 7 shown in FIG. 11 can employ a constitutionin which the cartridge body 8 is provided with a scale 20, and theradioactive source 10 charged can be calibrated in the same manner asabove.

(Shielding Cartridge)

FIG. 16 is a cross-sectional view of a cartridge 27 that is anotherembodiment of the present invention.

The above cartridge 27 has a cartridge body 28 made of a material thatis transparent and permits external visual observation (checking) of theradioactive source 10 and which itself can work as a shield againstradioactive rays.

In this embodiment, the cartridge body 28 per se can work as a shieldagainst radioactive rays without any shielding outer tube, so that theradioactive source that has been calibrated can be charged into thecartridge body 28 and a length of the radioactive source 10 can bechecked without any radiation exposure.

(Radioactive Source Having a Small Length)

When the radioactive source 10 has a length of less than 2 cm, and ifthe radioactive source 10 is positioned in the forward end portion ofthe connector tube 6 of the cartridge 7 or 17 shown in FIG. 11 or 14,the radioactive source 10 completely disappears in the connector tube 6and the head portion 5 or 5A of the cartridge body 8 or 18. There istherefore caused a problem that the calibration cannot be made in theabove method.

FIGS. 17 to 19 show structures of a cartridge that permits thecalibration of such a radioactive source having a small length. FIG. 17is a cross-sectional view of a cap C1, FIG. 18 is a cross-sectional viewof a cartridge 37 capped with the above cap C1, and FIG. 19 is aschematic drawing of a state in which an outer tube 39 of the abovecartridge 37 is slid backwardly in the longitudinal direction and acartridge body 38 is exposed.

The above cap C1 has a structure in which a spindle rod 22 is supportedon the center of end portion of an inner circumference of a protectionportion 21.

The above cartridge 37 is basically structured to have the same form asthat of the above cartridge 7, and an outer tube 39 is attached to anouter circumference of the cartridge body 38. As shown in FIG. 19, theforward end of the cartridge body 38 is provided with a head portion 5E,and an engagement portion 35C is formed in the backward end of the abovehead portion 5E. Further, an engagement portion 39A is formed in theforward end of the outer tube 39, and these engagement portions 35C and39A are formed to be engageable with each other.

The above cartridge 37 differs from the already explained cartridge 7 inthat a connector tube 36 having a smaller length than the connector tube6 is supported on the above head portion 5E. Another difference is thatthe surface of the cartridge body 38 is provided with a scale 30 thatextends in the longitudinal direction from the forward place thereof tothe backward place thereof and has divisions starting, for example, at 0up to 6 cm at intervals of 1 cm.

As shown in FIG. 19, the spindle rod 22 of the above cap C1 is insertedinto a passage 36A of the above connector tube 36, thereby to cap anouter circumference of the above connector tube 36 with an innercircumference of the protection portion 21. In this case, the length ofthe spindle rod or the length of insertion of the spindle rod into thepassage 36A of the connector tube 36 is determined to position theforward end of the above spindle rod 22 at 0 of the scale 30 provided onthe above cartridge body 38.

In this manner, the entire radioactive source 10 charged in thecartridge 37 appears in an encasing space 38A of the transparentcartridge body 38 and can be visually checked. Further, the forward endof the radioactive source 10 is brought into contact with the endportion of the spindle rod 22, whereby the forward end of theradioactive source 10 comes to 0 of the scale 30.

The calibration of the radioactive source 10 charged in the cartridge 37is carried out by sliding the outer tube 39 backwardly in thelongitudinal direction to expose the cartridge body 38 in the samemanner as in the calibration of the radioactive source 10 charged in theabove cartridge 7. That is, the entire length of the charged radioactivesource 10 can be clearly visually observed, so that the entireradioactive source 10 is directly accurately calibrated.

When the cap 21 having the spindle rod 22 is used as described above,the radioactive source 10 having a small length as small as less than 2cm can be calibrated and a conversion error can be avoided, so that amore accurate value can be determined.

The above technical idea can be applied to the cartridge 17 shown inFIG. 15. That is, in the cartridge 17, while the forms of the stopper 16of the head portion 5A of the above cartridge body 18 and the outer tube19 attached to the outer circumference of the cartridge body 18 areretained without any change, the connector tube 36 and the cap C1 asshown in FIG. 19 can be attached in place of the connector tube 6 andthe sheath 12. As described above, when the surface of outercircumference of the cartridge body 18 shown in FIG. 15 is provided witha scale 30 having divisions starting, for example, at 0 cm up to 6 cm atintervals of 1 cm, the entire radioactive source 10 can be constantlycalibrated irrespective of the length thereof, and, particularly, theradioactive source having a small length as small as less than. 2 cm canbe easily calibrated.

(Implanting of Radioactive Source)

The procedures of implanting a radioactive source in a body with atherapeutic material delivery device having the cartridge of the presentinvention will be explained with drawings.

FIG. 20 is a schematic drawing (partial cross-sectional view) forshowing one example of the procedures of implanting the radioactivesource 10 in a body, for example, with the delivery device 1′ having thecartridge 17 of the present invention. Further, the same procedures canbe employed for handling the above cartridges 7 and 27. In addition, thefollowing (1) to (8) corresponds to (1) to (8) in FIG. 20.

(1) For determining the sticking position of the outer needle 2, a plate11 for implanting the therapeutic material (radioactive source) (to besometimes abbreviated as “implanting plate 11” hereinafter) is arranged.The above outer needle 2 (outer tubular needle 2A) is stuck in asticking hole (intended position) of the above implanting plate 11. Theabove outer needle 2 has the middle needle 3 inserted therein. The outerneedle 2 that has stuck is monitored with an ultrasonic diagnosisapparatus inserted through an anus, to determine a position of theradioactive source.

In this embodiment, the above middle needle 3 not only works as areinforcement when the outer needle 2 is stuck in a body, but also isinserted into the outer needle 2 for preventing the spurt of body fluidssuch as blood and breakage of internal tissues. It is thereforepreferred to use a middle solid needle as the above middle tubularneedle 3A to be supported by the middle needle hub 3B of the middleneedle 3. The middle tubular needle 3A that can work as a reinforcementmay be used since the spurt of body fluids can be prevented by attachinga stopper to the middle needle hub 3B. In the present invention,therefore, the middle tubular needle 3A includes the above middle solidneedle when the middle needle 3 is used for the same purpose as that inthis embodiment.

(2) In a state where the outer tubular needle 2A is kept being stuck,the middle needle 3 is withdrawn from the above outer needle 2.

(3) There is prepared beforehand the cartridge 17 that is charged withthe radioactive source 10 to be implanted in a body and is finished withcalibration of a radiation dose.

(4) The forward end of the above cartridge 17 is connected to the outerneedle hub 2B supporting the outer tubular needle 2A.

That is, specifically, the outer needle hub 2B is formed by continuouslyintegrating a small-diameter portion 2B1, an intermediate-diameterportion 2B2 and a large-diameter portion 2B3, and the above sheath 12 isfitted in an inner circumference of the intermediate-diameter portion2B2. Further, the above cartridge 17 is pressed to bring the forward endof the head portion 5A into contact with the large-diameter portion 2B3.And, the forward end of the connector tube 6 is projected from theopening portion 12A of the sheath 12, and the outer circumference offorward end of the above connector tube 6 is engaged with the innercircumference of the small-diameter portion 2B1, so that the encasingspace 18A of the cartridge body 18 and the outer tubular needle 2Acommunicate with each other.

(5) The cap C capped on the backward end of the cartridge 17 is removed,to be ready for insertion of the inner needle 4 into the abovecartridge.

(6) The inner needle 4 is newly inserted through the backward end of thecartridge 17, to extrude the radioactive source 10 charged in thecartridge. The forward end of the cartridge 17 is engaged with the outerneedle hub 2B of the outer needle 2, and the solid needle 4A is insertedand moved forward until the backward end of the above cartridge 17 andthe forward end of the above inner needle hub 4B come to be engaged witheach other. In this case, the above therapeutic material 10 is extrudedthrough the forward end of the outer tubular needle 2A with the solidneedle 4A to be completely exposed. For this purpose, preferably, theabove solid needle 4A is formed so as to have a larger length than theabove outer tubular needle 2A.

(7) When the forward end of the above radioactive source 10 is implantedin an intended portion in a body through the outer needle 2, and whenthe backward end of the radioactive source 10 moves to reach the forwardend of the above outer needle 2 (that is, when the distance from theforward end of the inner needle hub 4 b of the inserted inner needle 4to the backward end of the cartridge 17 is a length L equivalent to thelength of the radioactive source 10), the extrusion with the innerneedle 4 is stopped.

(8) The inner needle hub 4B is fixed, and the outer needle 2 and thecartridge 17 are pulled in the direction of the inner needle hub 4B,whereby the radioactive source 10 is implanted in a body. Thereafter,the outer needle 2, the cartridge 17 and the inner needle 4 arewithdrawn from the interior of the body.

FIG. 21 is a schematic drawing (partial cross-sectional view) forshowing one example of the procedures of implanting the radioactivesource 10 in a body with the delivery device 1′ using the cartridge 37that is another type in the present invention.

When the cartridge 37 is used, the procedures are carried out almost inthe same manner as in the above procedures using the cartridge 17, sothat the procedures will be explained only with regard to those partsthat are different from the procedures using the cartridge 17.

As already discussed, the calibration of the entire radioactive source10 can be carried out beforehand with regard to the above cartridges 7and 17 by replacing the connector tube 6 and the sheath 12 with theconnector tube 36 and the cap C1 and further providing the surface ofouter circumference of each of the cartridge bodies 8 and 18 with ascale having divisions starting at 0 cm up to 6 cm at intervals of 1 cm.The above radioactive source 10 can be implanted in a body by the sameprocedures as those shown in FIG. 20.

(1) In the same manner as in FIG. 20(1), the above outer needle 32(outer tubular needle 32A) is stuck in the sticking hole (intendedposition) of the implanting plate 11. In the above outer needle 32, themiddle needle 3 having a middle solid needle supported by the middleneedle hub 3B is kept inserted.

As already described, the above middle needle 3 works as a reinforcementwhen the outer needle 32 is stuck in a body, and it is inserted into theouter needle 32 for preventing the spurt of body fluids such as bloodand breakage of internal tissues.

(2) The middle needle 3 is withdrawn from the above outer needle 32. Theabove outer needle 32 has the outer needle hub 32B supporting the outertubular needle 32A, and the above outer needle hub 32B has asmall-diameter portion 32B1 in a forward place and a large-diameterportion 32B3 in a backward place which portions are integrally formed.

(3) There is prepared beforehand the cartridge 37 that is charged withthe radioactive source 10 to be implanted in a body and is finished withcalibration of a radiation dose and from which the cap C1 is removed.The cartridge 37 is held horizontally.

(4) The forward end of the above cartridge 37 is connected to thebackward end of the outer needle hub 32B. That is, the forward end ofthe head portion 5E comes in contact with the large-diameter portion32B3, and the outer circumference of forward end of the above connectortube 36 comes to be engaged with the inner circumference of the smalldiameter portion 32B1, so that the encasing space 38A of the cartridgebody 38 and the outer tubular needle 32A come to communicate with eachother. The procedures (5) to (8) thereafter are basically the same asthose of handling the cartridge 17 explained with reference to FIG. 20,so that detailed explanations thereof are omitted.

(Effect of the Invention)

(I) According to the protective tool of the present invention or thedelivery device having the protective tool, attaching the protectivetool 68A or 68B to the outer needle 2 can produces effects that wrong oraccidental sticking of the outer tubular needle 2A after use isprevented and that no blood adhering to the above outer tubular needleis dissipated.

(II) Further, according to the cartridge of the present invention or thedelivery device using the cartridge, the following effects are produced.

(a) The cartridge 7 or 17 of the present invention having the outer tube9 or 19 obviates the calibration of a radioactive source before theradioactive source is charged in the cartridge. The radioactive source10 charged in the cartridge can be directly calibrated without exposingthe radioactive source 10.

(b) The cartridge 7, 17, 27 or 37 of the present invention has a headportion 5, 5A, 5B or 5E formed in the forward end thereof, and theconnector tube 6 or 36 is supported through the above head portion, sothat the above connector tube 6 or 36 does not break or bend under alateral strong force.

(c) The above connector tube 6 is capped with the sheath 12 having theopening portion 12A formed, and the sheath 12 is engaged with the innerwall of the outer needle hub 2B of the outer needle 2, so that theradioactive source 10 charged in the cartridge 7, 17 or 27 of thepresent invention can be extruded to the forward end of the outer needle2 without resistance.

(d) The outer circumference of the cartridge body 8, 18 or 28 of thecartridge 7, 17 or 27 of the present invention is provided with thescale 20, so that the radioactive source can be externally visuallychecked for a length. Further, on the basis of the above scale, theconverted value of calibration of the radioactive source 10 can beobtained.

(e) According to the cartridge 37 of the present invention in which theconnector tube 36 supported on the forward end of the cartridge body 38is capped with the cap C1, the surface of outer circumference of thecartridge body 38 is provided with the scale 30 having divisionsstarting at 0 cm up to 6 cm at intervals of 1 cm and the outer tube 39is attached to the outer circumference, the entire radioactive source 10can be directly calibrated, so that an error caused by conversion can beavoided.

(f) The cartridge body 28 of the cartridge 27 of the present inventionis made of a material that permits external visual observation of theradioactive source and can work as a shield against radioactive rays, sothat the charged radioactive source 10 can be externally easily checkedfor a length without exposure to radioactive rays.

1. A protective tool for a therapeutic material delivery devicecomprising an outer needle having an outer tubular needle and an outerneedle hub supporting the outer tubular needle, the protective toolbeing configured to be attached to said outer needle for the protectionthereof, the protective tool comprising a cover and a cap or stopperattached to a forward end of said cover for protecting the forward endof the outer tubular needle, wherein said cover is formed of a pluralityof tubes having different diameters that are formed so as toconsecutively decrease from a forward place to the outer needle hub in abackward place, and said tubes are thereby connected such that the coveris extendable in the longitudinal direction, wherein said cap has aninner tube formed inside, said inner tube has, made in a bottom thereof,a hole for inserting and passing said outer tubular needle, and saidinner tube has, formed in an outer circumference, a groove portion forinserting a forward end of said outer tubular needle.
 2. A protectivetool for a therapeutic material delivery device comprising an outerneedle having an outer tubular needle and an outer needle hub supportingthe outer tubular needle, the protective tool being configured to beattached to said outer needle for the protection thereof, the protectivetool comprising a cover and a cap or stopper attached to a forward endof said cover for protecting the forward end of the outer tubularneedle, wherein said cover is formed of a plurality of tubes havingdifferent diameters that are formed so as to consecutively decrease froma forward place to the outer needle hub in a backward place, and saidtubes are thereby connected such that the cover is extendable in thelongitudinal direction, wherein said stopper is constituted of a tubularopening/closing portion having a forward end and a connector portion,said opening/closing portion has slits formed in the longitudinaldirection, one in an upper portion and the other in a lower portion,said forward end has an opening portion, and said connector portion haspressing portions formed, one on the right and the other on the left,and has cutout grooves formed, one in an upper place and the other in alower place.
 3. A protective tool for a therapeutic material deliverydevice comprising an outer needle having an outer tubular needle and anouter needle hub supporting the outer tubular needle, a middle needlehaving a middle tubular needle and a middle needle hub supporting themiddle tubular needle and an inner needle having a solid needle and aninner needle hub supporting the solid needle, the outer needle, themiddle needle and the inner needle being to be connected for use, theprotective tool being configured to be attached to said outer needle forthe protection thereof, which protective tool comprises a cover and acap or a stopper that is attached to the forward end of said cover forprotecting the forward end of said outer tubular needle, wherein saidcover is formed of a plurality of tubes having different diameters thatare formed so as to consecutively decrease from a forward place to theouter needle hub in a backward place, and said tubes are therebyconnected such that the cover is extendable in the longitudinaldirection, wherein said cap has an inner tube formed inside, said innertube has, in a bottom thereof, a hole for inserting and passing saidouter tubular needle, and said inner tube has, formed in an outercircumference thereof, a groove portion for inserting the forward end ofsaid outer tubular needle.
 4. A protective tool for a therapeuticmaterial delivery device comprising an outer needle having an outertubular needle and an outer needle hub supporting the outer tubularneedle, a middle needle having a middle tubular needle and a middleneedle hub supporting the middle tubular needle and an inner needlehaving a solid needle and an inner needle hub supporting the solidneedle, the outer needle, the middle needle and the inner needle beingconfigured to be connected for use, the protective tool being configuredto be attached to said outer needle for the protection thereof, whichprotective tool comprises a cover and a cap or a stopper that isattached to the forward end of said cover for protecting the forward endof said outer tubular needle, wherein said cover is formed of aplurality of tubes having different diameters that are formed so as toconsecutively decrease from a forward place to the outer needle hub in abackward place, and said tubes are thereby connected such that the coveris extendable in the longitudinal direction, wherein said stopper isconstituted of a tubular opening/closing portion having a forward endand a connector portion, said opening/closing portion has slits formedin the longitudinal direction, one in an upper portion and the other ina lower portion, said forward end has an opening portion, and saidconnector portion has pressing portions formed, one on the right and theother on the left, and has cutout grooves formed, one in an upper placeand the other in a lower place.